1. Field of the Invention
The present invention related to enhancement mode FET having no body diode for synchronous rectification, used the characteristics of FET have gate minimization threshold voltage equal or over load voltage, FET is turn on, and used the characteristics of FET have gate minimization threshold voltage under load voltage, FET is turn off. According to such philosophy of the present invention, the synchronous rectification may be achieved with one N-Channel FET, or one P-Channel FET.
2. Description of Related Art
As shown in FIG. 5, a structure of the prior art single-ended forward converter circuit, has a pulse generator PG, a switching element SW, a high frequency transformer T1, a primary winding VP and secondary winding VS of the high frequency transformer T1, first terminal A and second terminal B of the secondary winding VS, a pair of first and second switching element F1, F2, a inductor L1, a capacitor C1, a load LD, and DC voltage output terminal C, D.
As shown in FIG. 5, when the positive of secondary winding VS in the terminal A, terminal B is negative, the switching element F1 is turned on, the switching element F2 is turned off, the path of the current flow is from terminal A of the secondary winding VS, though static shielding diode D2 of the switching element F2, switching element F1, and back to terminal B of the secondary winding VS, the possibility that F1, F2, may be burnout by current of the prior art N-Channel FET.